Sheet feed retarding mechanism for printing presses



y 1936. w. K. ECKHARD SHEET FEED RETARDING MECHANISM FOR FRiNTiNGPRESSES 5 Sheets-Sheet 1 Filed Jun 28, 1935 I 1 vi NSNSMW brn l Bi mamkm m 5:

VINVENTOR.

ATTORNEYS May 5, 1936. w. R. ECKHARD SHEET FEED RETARDING MECHANISM FORPRINTING PRESSES 3 Sheets-Sheet 2 Filed June 28, 1935 ATTORNEYS may 5,1936. K, ECKHARD 2,939,785

SHEET FEED RETARDING MECHANISM FOR PRINTING PRESSES Filed June 28, 19553 Sheets-Sheet 3 I INVENTOR. 8% W ATTORNEYS.

Patented May 5, 1936 UNITED STATES IPATENT OFFICE SHEET FEED RETARDINGMECHANISM FOR PRINTING PRESSES Application June 28,

4 Claims.

In sheet feed printing presses where a single mechanism has been usedfor retarding the travel of the sheets from the feeder to the frontsheet register or stop it has been found diificult to sufficientlyretard the travel of the sheets and deliver them in a normal fiatcondition because of the high speed of the feeder and the desirabilityof bringing the sheets down to a standstill at the front sheet registerbefore the sheets are taken by the sheet taking means.

The object of my invention is to obviate this difficulty by providingtwo coacting sheet straightening and retarding mechanisms locatedbetween the feeder and the front sheet register, the first sheetstraightening and retarding mechanism operating to receive the sheetsfrom the feeder at one speed, straighten them, and to.

transfer the sheets to the second sheet straightening and retardingmechanism at a slower speed, the said second sheet straightening andretarding mechanism operating to still further retard the travel of thesheets on their way to the front sheet register.

My invention more particularly comprises means for feeding sheets to thesheet register at progressively lesser speeds, comprising a sheet feederadapted to feed the sheets at a faster speed than the surface speed ofthe sheet taking means, the first sheet straightening and retardingmechanism including an endless chain carrier traveling at variablespeeds and having gages adapted to be engaged by the leading edges ofthe sheets as they are advanced by the feeder while the endless chaincarrier is traveling at a higher speed, and the second sheetstraightening and retarding mechanism including a reciprocating carrierhaving gages pivoted thereto, adapted to be engaged by the leading edgesof the sheets as the endless chain carrier is traveling at a lesserspeed.

A practical embodiment of my invention is represented in theaccompanying drawings, in which Fig. 1 represents in detail top plan somuch of a sheet fed rotary printing press and its feeding mechanism asincludes my invention, the parts being in the positions they assume whenthe swinging gages of the second sheet straightening and retardingmechanism;

Fig. 2 represents a side view of the same;

Fig. 3 represents a detail side elevation showing the parts in thepositions they assume as the swinging gages of the second sheetstraightening and retarding mechanism leave the sheet with its leadingedge engaged by the front sheet 1935, Serial No. 28,815

register in position to be taken by the grippers of the sheet takingmeans;

Fig. 4 represents a detail side view of the means for operating thefront sheet register;

Fig. 5 represents a detail enlarged top plan 5 view showing the relativepositions of the gages on the first and second sheet straightening andretarding mechanisms as the control of the sheets is about to be takenby the swinging gages of the second sheet straightening and retardingmechanism;

Fig. 6 represents a side view of the same;

Fig. '7 represents a detail side view of the second sheet retardingmechanism with the parts in the positions they assume when the swinginggages have dropped down out of the sheet path; and

Fig. 8 represents a similar View With the parts in the positions theyassume as the gages are about to be swung upwardly into position toreceive the leading edge of a sheet from the gages of the first sheetstraightening and retarding mechanism.

The sheet taking means is herein represented as an impression cylinderI, its shaft being denoted by 2, which cylinder is driven at apredetermined surface speed. The tumbler actuated grippers 3 on thecylinder I may be operated in the usual manner by the tumbler cam 4 andits coacting pin 5, to take a sheet from the front sheet register at theproper time; the pin for actuating the tumbler cam for delivering thesheet not being shown herein as it forms no part of the presentinvention.

The front sheet register may be of any well known or approvedconstruction. In the form herein shown the front sheet stops 6 arecarried by the spring pressed rock lever I, which lever is in turnoperated by the spring pressed rock lever 8 which carries a stud orroller 9 contacted by the cam In on the cylinder shaft 2, to swing thefront sheet stops 6 downwardly out of engagement with the leading edgeof the sheet as it is grasped by the cylinder grippers 3. It is obviousthat two or more of these front sheet stops are provided to properlyfront register the sheet before it is taken by the cylinder grippers.

The means which I have shown for feeding the sheets at successivelyreduced speeds to the front sheet stops 6 is constructed, arranged andoperated as follows:

The inner end of the endless tape carrier of the sheet feeder is shown,which tape carrier is arranged to feed the sheets at a speed faster thanthe surface speed of the cylinder I. These tapes ll of the endless tapecarrier pass around the pulleys l2 carried by the cross shaft l3 at theinner end of the carrier.

The first sheet straightening and retarding mechanism includes twoendless chains 14 (one only of which is shown herein) overlapping theendless tape carrier in substantially the plane of the sheet path, whichchains are driven at varying speeds. These endless chains pass aroundinner and outer sprockets I5 and I6 carried by the stud shafts I! and I8respectively. These chains are provided with alined front sheet gages orhooks |9 arranged in position to receive the leading edge of the sheetat one speed as it is advanced by the sheet feeding tapes I and totransfer the leading edge of the sheet to the second sheet straighteningand retarding mechanism at a lesser speed.

The second sheet straightening and retarding mechanism includes twocarriages (one only of which is shown herein) reciprocating on tracks 2|toward and away from the front sheet register stops 6 in substantiallythe plane of the sheet path. The said reciprocating carriages 20 areprovided with swinging spring pressed front sheet gages or hooks 22pivoted thereto to be swung into andjout of the sheet path. These frontgages 22 are adapted to receive the leading edge of the advancing sheetfrom the gages |9 on the endless chains M of the first sheetstraightening and retarding mechanism at a surface speed slightly slowerthan that of the said gages 9 and rapidly retard the travel of the sheetuntil its leading edge reaches the front sheet register stop 6.-

The means for reciprocating each'carriage 29 of the second sheetstraightening and retarding mechanism comprises a rotary cam 23 mountedon the cross shaft 24, the face of which cam is v contacted by a stud orroller 25 carried by a spring pressed rock lever 26. This rock lever 26is connected by a rod 21, toanother rock lever 28 which in turn isconnected by a rod 29 to the carriage 253. It will be understood thatthe face of the cam 23 is so shaped that at the time the gages 22 of thesecond sheet straightening and retarding mechanism receive the leadingedge of the advancing sheet from the gages I9 of the first sheetstraightening and retarding mechanism the carriages 29 will be travelingslightly slower than the gages 9. Immediately after the gages 22 havereceived the leading edge of the advancing sheet the carriages 20 aredecelerated so that the leading edge of the advancing sheet reaches thefront sheet register stop at a greatly reduced speed.

The means for swinging each of the gages 22 of the second sheetstraightening and retarding mechanism into and out of the sheet pathincludes a stud or roller 30 carried by the gage, which stud or rolleris caused to travel in an endless path by providing a cam groove 3| ineach side of the tracks 2|, which cam' groove opens at its inner andouter ends through the top of the track. These cam groove openings areso arranged that as the carriage 20 reaches the inward limit of itssliding movement the stud or roller 30 will drop into the cam groove 3|and thus swing 'the gages 22 out of the sheet path. A plate spring 32located in the cam groove 3| is so positioned and shaped that the studor roller 30 will force the free end of the spring laterally out of theway on the outward sliding movement of the carriage and will permit thespring to snap back to its normal position as the carriage reaches thelimit of its said outward movement. The stud or roller 30 will be causedto ride up out of the cam groove on the inclined outer edge of thespring 32 as the carriage is started on its inward sliding movement.This will swing the gages 22 upwardly into the sheet path in position toreceive the leading edge of the advancing sheet from the gages H! on theendless chains of the first sheet straightening and retarding mechanism.

The means which I have shown for. imparting thevariable speedto theendless chains l4 of the first sheet straightening and retardingmechanism is as follows:

An eccentric gear 33 mounted on the cross stud shaft I8 is driven by aneccentric gear 34 mounted on a cross shaft 35. This cross shaft 35 isoperatively connected to the cam shaft 24 through the trainof gears36,31, 38, 39, and 4|. 'The cross shaft |3 for the pulleys |2 at theinner end of the sheet feeding endless tape carrier is operativelyconnected to the cam shaft 24 through the train of gears 42, 43, 44, and46. The gear 4| on the cam shaft 24 is operatively connected through thegears 41' and 48 to the gear 49 on the cylinder From the abovedescription it will be seen that I have provided means whereby the firstsheet straightening and retarding mechanism may receive the sheets fromthe sheet feeder at a certain speed and then rapidly retard the travelof the sheets before transferring them to the control of the secondsheet straightening and retarding mechanism; which latter mechanismstill further retards the travel of the sheets on their way to the frontsheet register.

It will be understood that the sheet feeding mechanism herein shown anddescribed is to be used in connection with the usual side registeringand sheet detecting mechanism not shown herein.

It is evident that various changes may be resorted to in theconstruction, form and arrangement of the several parts withoutdeparting from the spirit and scope of my invention,- and hence I do notintend to be limited to the particular embodiment herein shown anddescribed, but what I claim is: I

1. In a printing press, a front sheet register and means for feedingsheets thereto comprising, a sheet feeder and coacting first and secondsheet straightening and retarding mechanisms, the first sheetstraightening and retarding mechanism operating to receive the sheetfrom the feeder at one speed and gradually retard the sheet, and thesecond sheet straightening and retarding mechanism operating to receivethe sheet from the first sheet straightening and retarding mechanism andstill further retard the sheet on its way to the front sheet register.

2. In a printing press, a front sheet register and means for feedingsheets thereto comprising, a sheet feeder and coacting first and secondsheet straightening and retarding mechanisms traveling in differentlooped paths, the first sheet straightening and retarding mechanismoperating to receive the sheet from the feeder at one speed andgradually retard the sheet, and the second sheet straightening andretarding mechanism operating to receive the sheet from the first sheetstraightening and retarding mechanism and still further retard the sheeton its Way to the front sheet register.

3. In a printing press, a. front sheet register and means for feedingsheets thereto comprising, a sheet feeder and coacting first and secondsheet straightening and retarding mechanisms having gages traveling indifferent looped paths, the gages of the first sheet straightening andretarding mechanism operating to receive the sheet from the feeder atone speed and gradually retard the sheet, and the gages of the secondsheet straightening and retarding mechanism operating to receive thesheet, from the gages of the first sheet straightening and retardingmechanism and still further retard the sheet on its way to the frontsheet register.

4. In a printing press, a front sheet register and means for feedingsheets thereto comprising, a sheet feeder and coacting first and secondsheet straightening and retarding mechanisms, the first mechanismincluding endless chains having gages for receiving the sheet from thefeeder at one speed and for transferring the sheet to the secondmechanism at a lesser speed, the said second mechanism includingreciprocating carriages having gages traveling in a looped path andoperating to still further retard the sheet on its way to the frontsheet register.

